Condensed Consolidated Statements of Operations (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Income Statement [Abstract]
Sales, net	$ 11,746	$ 7,380
Expenses
Cost of products	6,909	5,143
Selling, general and administrative	4,089	3,443
Total expenses	10,998	8,586
Operating income (loss)	748	(1,206)
Other income (expense):
Interest income	17	8
Loss on investment in securities	(1,146)	0
Loss on disposal of property, plant and equipment	0	(104)
Other expense	(168)	(87)
Total other income	(1,297)	(183)
Loss before taxes	(549)	(1,389)
Income tax benefit	106	121
Net loss	$ (443)	$ (1,268)
Net loss per share-basic	$ (0.03)	$ (0.09)
Net loss per share-diluted	$ (0.03)	$ (0.09)
Weighted average shares outstanding-basic	13,754,119	13,734,053
Weighted average shares outstanding-diluted	13,754,119	13,734,053